HEVC fast reference picture selection

Abstract

The new high efficiency video coding (HEVC) standard facilitates the realisation of ultrahigh-definition video applications. Although the compression efficiency of the HEVC standard is double that of the well-established H.264 standard, HEVC incurs a considerably higher encoding complexity. This Letter presents an algorithm aimed at expediting reference picture selection processes in HEVC encoding. The proposed algorithm is primarily based on a reference picture and block discovered using the advanced motion vector prediction (AMVP) algorithm. Two acceleration conditions are included in the proposed algorithm. The first early-decision condition entails examining the rate-distortion (RD) cost associated with AMVP, and if this cost is lower than a predefined threshold, motion estimation is confined to the AMVP-selected reference picture. Furthermore, for coding units of size 64 × 64 (N = 32) with a prediction-unit (PU) partitioning of 2N × N or N × 2N, the second PU uses the same reference picture as the first PU if the first PU satisfies the first early-decision condition. The experimental results revealed that the proposed algorithm considerably reduced the total encoding time with negligible RD degradation.